Recycling of waste matter by reacting the waste in a flame is a desirable alternative to permanent storage or burial, especially if the matter to be recycled is environmentally questionable or known to be hazardous. Examples of such waste matter include fiberglass, mineral wool, and industrial solvents. By burning instead of storing or burying the waste matter, the need for landfill space is eliminated. Additionally, the potential health risks associated with future human contact with the waste matter are also eliminated.
Reacting waste matter in a flame envelope, however, introduces concerns regarding by-products of the reaction processes. The reaction of the waste matter in the flame includes many processes, including burning, melting, incineration, combustion, fusion and oxidation. The term "react", or any derivatives thereof, as used herein means one or more of these processes.
Some of these reaction processes yield by-products. For example, reacting waste matter in a natural gas flame, combusting in air which is 80% nitrogen, yields measurable quantities of NO, N.sub.2 O, and NO.sub.2. These are primary components of the so-called "acid rain", or precipitation abnormally high in nitric acid content. Moreover, the temperature of a natural gas flame burning in air can reach only about 3500.degree. F. If the natural gas flame is oxygenated to 100% oxygen with pure oxygen, no nitrous by-products are created by the combustion media, and flame temperatures upwards of 5000.degree. F. can be obtained. The increased flame temperature obtained by oxygenating the flame is advantageous in reacting flame resistant waste matter which requires extremely high temperatures, or oxidizing atmospheres, before reacting in the flame.
Although methods and devices are known for reducing nitrous by-products in gas burners, and for oxygenating gas burner flames to ensure rapid and complete combustion of the gas, it is not known to provide means for directly injecting waste matter mixed with an oxygen-containing gas into an oxygenated flame envelope of a gas burner. For example, Sato, et al. U.S. Pat. No. 4,531,904 discloses an apparatus and a method for reducing the NO.sub.x gas content in the exhaust yielded by a gas burner. Fuel nozzles are disposed intermediate peripheral and central air nozzles. The exit apertures of the peripheral air nozzle and the fuel nozzles are coplanar while the central air nozzle extends beyond this plane. The fuel is primarily burned in the zone near the fuel nozzle and peripheral nozzle apertures, and is secondarily burned in the zone near the central nozzle aperture. The NO.sub.x content of the exhaust gas is minimized by controlling the rate of combustion in these two zones, and by controlling the amount of air supplied to the flame.
Similarly, U.S. Pat. Nos. 3,817,685 to Joannes and 4,428,727 to Deussner, et al. disclose devices designed to ensure complete burning and rapid combustion of fuels provided to the burners. Deussner discloses a multi-level burner adapted to create a turbulent suspension of particles in the primary air stream, creating an aspirating effect for drawing secondary air into the burner along with the turbulent suspension of solid fuel particles t accelerate the combustion process. Joannes discloses a burner wherein fuel is combined with air carried by an air supply pipe, and a shroud element surrounding the air supply pipe creates a region of low pressure which draws the burned gases back into the burning zone to ensure complete combustion. Deussner, Joannes, and Sato, however, all fail to disclose apparatuses or methods for injecting waste matter into a burner flame envelope to ensure rapid and complete reaction of the waste matter.
In addition to reducing the nitrous by-products and increasing the flame temperature of a waste recycling apparatus, it is useful to increase the adaptability of such an apparatus by providing means to cool the apparatus during extended high-temperature use, and by providing apparatus elements which are interchangeable to accommodate reaction of various types of waste. By using interchangeable elements, the rate and pattern of waste, fuel and oxygen injection can be controlled to ensure the proper rate and extent of reaction of a particular waste in the flame.
Although interchangeable burner parts are known, their application is limited to torch heads rather than waste ejecting nozzles. For example, Roeder, et al. U.S. Pat. No. 4,192,488 and French Publication No. 2,637,050 to Rathert disclose such torch heads. Again, as with all of the previously discussed patents, neither of the above two patents having interchangeable torch heads provides a method or apparatus for injecting waste matter directly into a flame envelope to control the rate and degree of reaction of the waste matter in the flame.
Thus, there is a need to provide an apparatus and method for reacting waste matter in an oxygenated flame to ensure rapid and efficient reaction of the waste matter, which is adapted for high temperature application and which has the capability to react a variety of wastes by controlling the rate and extent of reaction of the waste in the flame. The present invention addresses this need.